The PSG Core Laboratories continued to provide critical technical pathology support services and scientific collaborations and consultation for research laboratories across the NIEHS. Over the past year, collaborative and support oriented work has had a significant impact on a spectrum of research programs involved in the study and understanding of a variety of diseases and disease processes such as cancer; molecular pathology and genetics; respiratory, cardiovascular (atherosclerosis), reproductive, neurological, metabolic, inflammatory and immune diseases; obesity; Type II diabetes; gene expression, regulation and mutation; axioskeletal development; and the transgenerational effects of diet restriction. The scope of work continues to increase across all of the Core Laboratories, as have collaborations and consultations with scientific staff whether on a technical level regarding the methods required, or on a scientific level, requiring consultation with a staff pathologist. Core technical staff continue to work closely with investigators to design and develop protocols and establish specialized techniques for a variety of applications. Additionally, using biological specimens collected during the conduct of DNTP animal bioassays, the Cores have provided support for retrospective studies aimed at elucidating the pathogenesis and molecular mechanisms involved in the development of variety of proliferative non-neoplastic and neoplastic lesions. PSG pathologist have provided timely and important histopathological evaluations and interpretations for several investigators which have allowed them to further their research projects and have as valuable contributions to their scientific publications and presentations.